Artikel Jurnal
Slauerhoff, Jan Jacob, author
Djambatan, 1977
Buku Teks
World Health Organizaion, Regional Office for South-East Asia, 1988
Buku Teks
Situmorang, Sitor, 1923-2014, author
Gramedia, 1989
Buku Teks
Cady, John F.
Harvard University Press, 1976
Buku Teks